Do you know where to find one?

I'm still screening ideas for powering some EL tape, which needs ~400Hz-2kHz at ~120V rms. Power in the 10W or more range would be fine.

Since the required frequency is in the audio range, I'm wondering if a cheap class D audio amp might do the job for me. I could feed it 165V DC and use a signal generator to provide a line-level signal at the desired frequency. I don't care about fidelity so much as power efficiency.

Most class D boards I've seen on e-bay and elsewhere are meant for lower rail voltages, ±35V and less. Automotive, I guess. The chip makers like TI and IR have literature on ICs that can handle 200V or more but I don't see devices anywhere that take advantage of that. Maybe they're not in the cheap range.

Any ideas where to look?

 

Does EL wire require a sine wave? If not, why not just run an H-bridge with a square wave? Perhaps an LC filter to smooth it out.

Bob

 

It's hard to say. EL tape or wire is described as a leaky capacitor, with part of the power leakage being the light that is produced. Once the voltage exceeds a minimum, the intensity of light is said to be proportional to both voltage and frequency. Aging of the EL material is inversely proportional to V and ƒ also. If I recall correctly, age is extended by minimizing voltage and using frequency to get the brightness but don't quote me on that.

Everything I've considered so far would produce a square wave, more or less, and it concerns me that the edges of the square wave might be hard on the EL material. I frankly have no idea if that matters, but I'd feel better if I could supply a sine wave or maybe even experiment with different wave shapes.

I've consider feeding a 12V square wave into a (capacitively coupled) wall wart transformer run in reverse, to generate >120V AC. Another option is chopping DC at ~160V into a square wave. I'm confident that both of these will work, but I'm still looking for more options. The transformer may suffer from saturation at higher frequencies.